Help with UHC-S filter

[Jaume]

Hi
Last night I did some photos (200 pictures , ISO 800, 20”) of NGC7380 whit my Nikon DSLR and the Baader UHC-S filter for light pollution.
I used DSS for stacking like I read in some tutorials, and approximately 150 pictures were staked.
At last, I have a fit file, that I open with Star tools. Then I use BIN (75) -> Autodev -> Crop-> Wipe (using Mask with Lasoo for the nebula) -> Vignetting ( Dark anomaly filter 5 pixels) -> Do
After that the image is fine. But I can’t see the nebula.
The I Use Develop, sliding until 90-92%.
The nebula is not in the image but I’m sure that is in there.
What can I do? Can you Help me?
Thanks

[admin]

Hi
Last night I did some photos (200 pictures , ISO 800, 20”) of NGC7380 whit my Nikon DSLR and the Baader UHC-S filter for light pollution.
I used DSS for stacking like I read in some tutorials, and approximately 150 pictures were staked.
At last, I have a fit file, that I open with Star tools. Then I use BIN (75) -> Autodev -> Crop-> Wipe (using Mask with Lasoo for the nebula) -> Vignetting ( Dark anomaly filter 5 pixels) -> Do
After that the image is fine. But I can’t see the nebula.
The I Use Develop, sliding until 90-92%.
The nebula is not in the image but I’m sure that is in there.
What can I do? Can you Help me?
Thanks

Hi there, welcome to the StarTools forums!

Your problem is most likely that NGC 7380 is extremely faint. From a light polluted location and using just 20" frames, chances are that you simply did not get enough signal.
If you're just getting started, and depending on your location and light pollution, I would try some other, easier objects first. E.g. M42, M8, or the Carina nebula if you're in the Southern hemisphere.
That said, if you definitely feel the signal is there, feel free to share your stack with us here (e.g. through Dropbox, Google Drive or similar).

Clear skies!

[Jaume]

Hi
Here are the pictures stacked with DSS
https://drive.google.com/file/d/1EWrQwN ... sp=sharing


And the same pictures stacked with Nebulosity
https://drive.google.com/file/d/1onYWmK ... sp=sharing

Thanks for your help

[admin]

Hi,

Thank you for uploading. I just had a look at the data.
Unfortunately, it is as I feared; there is simply not enough signal in your stack.
Most of all though, you need to take flats; they are not optional, especially when you go for very faint objects like these. Any faint nebulosity you might have recorded is overwhelmed by uneven lighting and vignetting.
My original advice still stands - if you can't go longer than 20 seconds (I see some field rotation in your subs, correct?) cut your teeth on easily acquired objects such as M42, M8, M31, etc.

I hope this helps & wish you clear skies!

[Jaume]

Thanks for your help!

[almcl]

In addition to following Ivo's expert advice, you are not quite on target. Image below (from Astrometry.net) shows NGC 7380 is just out of frame on the right. If you can get it centred you may find that the Wizard can be picked out?